Winton Davies <[email protected]> writes:

> I had no way to ground test it.

My experience with BP charges suggests that anything smaller than about
0.7g is kind of "twitchy" unless you do a great job of containment so
that it all burns cleanly.  You didn't say anything about how you
constructed the charges, though?

> I believe the motor ejection charge fired first - just pre-apogee

Looks that way to me, too.

> looks like they both fired. But the
> voltage drops were different - the aft drogue appeared to have a tiny
> drop, but the main showed a huge drop. 

This is not unusual.  It depends on whether the e-match goes "open" when
it fires or remains conductive.  That depends on the design of the
match, and I think also on how your build your charges and how much
force is applied to the match head.  See my recent blog post about
batteries and pyro charges for more commentary on this.

> From ground observation it looked liked the 4F charge was too small to
> cleanly blow the chute packages (drogue was a reefed 30") out - and
> they seemed to wriggle out slowly and only fully inflate a 100' or so
> off the ground. I think this can be seen by the relatively constant
> descent velocity, that only slows down just before reaching ground
> level.

Sounds like you recovered the airframe ok, though?  If I were making
charges in surgi tubing I'd probably do 0.7g with the match head right
in the middle of the BP if I could for the next try...

> Anyway, I'd love to have your experienced read on this! It was so cool
> having the live GPS talking during the brief flight, had a bunch of
> interested folk around us at NASA Ames/Moffet Field.

Cool!

Bdale

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